Qblox ICCs - Hotfix for storing scope acquisition (broken by !432) (QAE-469)

Explanation of changes

MR !432 (merged) fixed selecting scope acquisition sequencer

• we were still supplying strings "seq0" but instrument.scope_acq_sequencer_select now expects indices; hence, scope acq seq would always be the default of 0

However, in changing scope_mode_sequencer to be an index instead of string, _store_scope_acquisition got broken:

• sequencer_index = self.seq_name_to_idx_map.get(self.scope_mode_sequencer) would return None
• after which self.instrument.store_scope_acquisition(sequencer_index, acq_name) would never be called

This hotfix addresses that by simply directly taking sequencer_index = self.scope_mode_sequencer.

Motivation of changes

Simple fix, pushing out the hotfix first (and making sure existing tests pass), will then in a follow-up MR tend to adding additional tests to guard against this happening again. @v_m_patel has already validated the fix on hardware, so checking that box.

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Merge checklist

See also merge request guidelines

• Merge request has been reviewed (in-depth by a knowledgeable contributor), and is approved by a project maintainer.
• New code is covered by unit tests (or N/A).
• New code is documented and docstrings use numpydoc format (or N/A).
• New functionality: considered making private instead of extending public API (or N/A).
• Public API changed: added @deprecated (or N/A).
• Tested on hardware (or N/A).
• CHANGELOG.md and AUTHORS.md have been updated (or N/A).
• Windows tests in CI pipeline pass (manually triggered by maintainers before merging).

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